The present invention relates to cleaning optical fiber ribbons and, more particularly, to an optical fiber ribbon cleaning apparatus that cleans optical fiber ribbons while ensuring that the ribbons remain flat so that the individual optical fibers of the ribbon are not separated during the cleaning process.
Optical fibers are widely used as a signal transmission media. Their popularity stems from both their small size and from their large bandwidth capability, which is orders of magnitude greater than electrical conductors. However, optical fibers are mechanically fragile and exhibit low strain fracture resistances under tensile loading. In addition, optical fibers cannot be sharply bent. This is because the propagation of light through optical fibers can be seriously degraded by too sharp a bend, and the fiber itself can be fractured by such a bend. The fibers, when assembled into a cable, must be capable of withstanding tensile loads and bending stresses caused when the cable is pulled along its routing and through turns.
In order to achieve high fiber count cables with high fiber packing densities the optical fibers are produced and then bonded together so as to provide a fiber array or ribbon containing multiple fibers. The ribbon may have any number of fibers, but the fibers are commonly assembled in a co-planar array having four, six, eight, twelve, sixteen, twenty-four, or more fibers. A twelve-fiber ribbon currently is the most widely used. As the use of such ribbons increases, the number of fibers in the array is also expected to increase, and cables or ribbons with hundreds or thousands of individual optical fibers are possible and even likely to appear in he future. Such ribbons and a method of producing them are described, respectively, in U.S. Pat. No. 4,900,126 to Jackson et al. and U.S. Pat. Nos. 4,980,007 and 5,076,881, both to Ferguson.
As discussed in these patents, the optical fibers comprising a ribbon are typically color-coded and held together by a matrix, which secures the fibers in the desired planar array, or ribbon, of optical fibers. The matrix is typically made from an ultra violet light-curable urethane acrylate and is coated with a cable-filling compound. The ribbons are typically disposed within a tube-like covering and are encapsulated with a grease-like cable filling compound that guards against water ingress and migration. Consequently, dirt, dust, and other contaminants easily adhere to a ribbon coated with the compound. Therefore, the cable-filling compound is wiped from the ribbon when the optical fibers are spliced, or when the ribbon is placed within an environment where it is undesirable to have grease present.
The current technique used for removing the cable-filling compound from the ribbon often involves soaking the ribbon in a cleaning solution, which typically is alcohol or citrus-based, and then wiping the ribbon with a cloth to remove the cable-filling compound from the ribbon. This process of cleaning a ribbon tends to be messy because the cleaning solution and/or the cable-filling compound may drip onto the floor or onto the person cleaning the ribbon. Furthermore, cleaning a ribbon involves the use of large quantities of consumable wiping clothes.
Furthermore, this cleaning process may damage the ribbon. When wiping the ribbon by hand, the ribbon may be twisted or bent, or both, thereby resulting in the accidental splitting of the ribbon. The task of cleaning a ribbon without accidentally splitting it is even more difficult for wider ribbons and in congested spaces such as manhole.
Accordingly, a need exists for an apparatus for removing the cable-filling compound, or other materials, from an optical fiber ribbon quickly and easily while also preventing the ribbon from being damaged.
The present invention provides an apparatus for cleaning an optical fiber ribbon without splitting the ribbon. The apparatus comprises a first element that has a channel formed therein, which preferably has a width that is substantially equal to the width of an optical fiber ribbon. The channel defines a flat surface for receiving an optical fiber ribbon to be cleaned. A ribbon is cleaned by disposing it in the channel and by pulling the ribbon through the channel while applying a force to the top surface of the ribbon to thereby maintain the ribbon flat against the channel. For example, a user applies a cleaning device, such as a sponge or cleaning cloth, to the top surface of the ribbon as it is pulled through the channel in a direction parallel to the lengthwise direction of the ribbon. The contact between the channel, the cleaning device and the exterior surface of the ribbon effectuate removal of foreign material from the exterior surface of the ribbon.
In accordance with the preferred embodiment of the present invention, the apparatus further comprises a second element. The second element includes a bottom surface that is disposed over the channel formed in the first element when the first and second elements are placed in their respective operative positions. In order to clean a ribbon, the ribbon is disposed flatly in the channel of the first element and the second element is placed in contact with the first element such that the bottom surface of the second element covers the ribbon. The ribbon, or a section of the ribbon, is then pulled through the channel in a direction parallel to the length-wise direction of the ribbon. As the ribbon is pulled, the channel of the first element and the bottom surface of the second element cooperate to perform a wiping action that removes unwanted particles or matter from the outer surface of the ribbon. The channel of the first element and the bottom surface of the second element maintain the ribbon in a flat configuration as it is being pulled, thereby preventing the ribbon from splitting.
The apparatus preferably also comprises a coupling device for coupling the first and second elements together. The coupling device allows the apparatus to be easily opened and closed to thereby allow a ribbon to be easily placed in and removed from the ribbon cleaning apparatus of the invention. Preferably, the ribbon cleaning apparatus is a hand-held apparatus that can be held in one hand by a user while the user pulls the ribbon with the other hand in order to clean the ribbon. Preferably, the channel is integrally formed in the first element and the first and second elements are comprised, at least partially, of a conformable material that conforms to the exterior surface of the ribbon during the cleaning process.
These and other features and advantages of the present invention will become apparent from the following description, drawings and claims.